Large pressurized tanks conventionally contain compressed gases for use in medical treatments and procedures. These tanks are usually heavy, bulky end quite inconvenient to transport. They can also present a dangerous risk of explosion. Refilling such tanks also tends to be time consuming and logistically inconvenient. In addition, pressurized full-sized tanks are also apt to harbor mold, debris and rust within the tank. This can seriously jeopardize the quality and integrity of the accommodated gas. Contaminants are highly undesirable in medical applications where toe gas should exhibit a high degree of purity.